How to Plant Trees and Shrubs
- Gardening Expert and Host of Growing a Greener World®April 5, 2022
Learn the Right Way to Plant Trees and Shrubs - Seven Steps to Ensure Success
In my experience, there are seven key steps to ensure full establishment of newly planted trees and shrubs. And fall is the absolute very best time to get them in the ground. Simply stated, if you want to give your plants the best chance of establishing in the landscape by next spring, plant them in fall!
Before I get into the seven important steps to planting success, let me explain why fall is the best time for planting trees and shrubs.
First, this season offers the maximum amount of time for new plants to settle in before the heat and stress of next summer.
Secondly, above ground, the cooler air is kinder to plant foliage and reduces the chances of an energy-zapping chain reaction throughout the rest of the plant. Beneath the surface, soil temperatures are still warm which provides an excellent environment to stimulate and foster new root growth. Collectively, it’s the cooler air and warm soil temperatures of autumn that make for the best combination for establishment. If you plant in fall, in most, but not all cases, they should be well-established by next summer.
The third benefit to fall transplanting is that many plants and trees are entering a period of dormancy. Without the need to allocate resources into foliage, plants now shift their energy into root development and storing nutrients and resources for the cool months ahead. While conditions are most favorable now, that is not to say you just plant it and forget it.
For the best chance of success, follow these seven important steps for all your fall transplants to reach their full potential:
Learn the Five Most Common Tree Mistakes
1. Prepare the proper planting hole for trees and shrubs.
How deep should the soil be when planting trees and shrubs? When preparing any hole for tree planting, make it two to three times wider than the current root mass but never deeper than the plant was growing in its previous environment. With trees, an even better guide is to look for the flare of the trunk near the soil level. Don’t place the tree in the planting hole so deep that any part of that flair is covered with soil. The truth is, even nurseries sometimes put plants in containers too deeply. There have been many times where I’ve actually had to pull away soil to find the base of the trunk flair and true surface roots. Make a habit of checking this.
2. Plant trees and shrubs high.
I go even one step further by placing transplants in their new environment with up to 25% of the root ball higher than the surrounding soil level. I then taper the soil up to cover all the roots and add a generous layer of mulch above that. Newly disturbed soil has a tendency to settle and shrubs and trees planted below grade can easily succumb to root rot or disease. In my book, it’s always better to plant a tree or shrub slightly high and allow the area to drain than for a plant to sit in a bowl and collect excess water. More plants die from over-watering (drowning) than under watering.
Tip: An easy way to know if your hole is at the right depth is to take your shovel handle and lay it across the grade. The top of the root ball or tree flare should be at or above the handle level.
3. Inspect tree roots and disturb them when necessary.
Once the plant is out of its container, look at the roots. If they are densely bound in a circular pattern or have started growing in the shape of the container, break up the pattern. I can’t emphasize this enough!
It’s more important to stop this pattern now than worry about hurting the roots. The biggest mistake you can make at this point is to place a root-bound plant into the ground as is. Unless you break up the pattern, you’ve likely sentenced the plant to a slow (or rapid) death. At a minimum, it will likely never establish or reach a fraction of its potential. Keep in mind, this is your only real chance to do this. And if you’re hiring someone to do your planting for you, insist they do the same. I have seen many trees and shrubs die within months of planting because no one took the time to break up the root-bound pattern. Even though the plants were being watered, the roots were so tightly wound, they couldn’t take it up.
Don’t worry about hurting the roots or losing soil as you break the roots apart or even cut some away. Better to give them a fresh start than allow the constrictive pattern to only get worse below ground. While you don’t want to be any rougher than necessary, do what you must to arrest the pattern. I often scratch my fingers across the sides and bottom of the plant, even in mild cases. In more severe situations, I’ll slice up the roots vertically, hack off the bottom inch or so, and or pull apart the root mass to clearly create opportunities for non-circular new root development.
4. When to amend the soil.
Another reason for digging a wide planting hole is to provide the best opportunity for roots to expand into their new growing environment. Unfortunately, all too often, we dig a hole that is barely wide enough for the root ball and expect to compensate by adding some soil amendments. While in theory, this sounds reasonable, in practice, it’s a false sense of security that can lead to poor establishment.
I’ll be the first to say, any time you can improve your soil with organic matter or Certified Compost is almost always a good thing. But in cases where the planting hole is insufficiently wide, studies show roots tend to not spread out into beyond the narrow planting hole, instead opting for the luxury conditions of the amended soil where they tend to stay. Instead, dig a hole wide enough to reasonably accommodate the root zone at a plant’s maturity. The benefit is ample opportunity for full root expansion, and in a soil environment that is greatly improved.
5. Eliminate air pockets when planting trees.
Be sure to lightly tamp or hand-pack the soil around the plant roots to ensure good soil to root contact. I add water to the hole after backfilling half way. Not only does it provide needed moisture but also the water helps eliminate air pockets that could otherwise result in dead roots.
Water again thoroughly once all the soil is in place. I like to use a hose-end nozzle or wand that delivers a strong blast of water to break up clumpy soil and allow new soil to fill in and settle into those vacated air pockets.
6. Add mulch.
Place about three inches of organic matter such as shredded leaves, or ground bark, or wood mulch around the plant, at least out to the drip line. Further is better. Mulch helps retain much-needed moisture and helps keep roots cooler near the surface—a very important requirement for newly installed plants.
7. Watering new trees and shrubs.
The most important job you will have after planting is to keep plants and trees well-watered until established. This can take weeks to months to even a year!
Since installing over 200 trees and shrubs in my landscape this fall, I’ve watered every plant every day (here in Atlanta) for about the first two weeks. For the next two weeks, I ease off slightly but no less than every other day. Then gradually ease back from there.
Be aware there’s a fine line between watering enough and watering too much—especially with large trees that arrive with root balls wrapped in burlap. These trees have lost all their feeder roots when dug from the ground. Providing adequate water is critical to their survival and establishment. Yet I’ve killed more than one tree like this by over-watering. Even if you prepare a large planting hole when drainage is poor, the root ball may be sitting in water and literally drowning, and you won’t know realize it until it’s too late.
There’s no easy way to know deep down how wet the soil is. The best advice I can offer is to pay close attention to how the tree responds (and all your plants for that matter). While it’s common for them to lose up to half their leaves to stress (a normal part of the process), more can indicate a potential problem. If you sense the tree is responding poorly, and you are watering consistently, you’re likely over-watering. If the leaves are turning brown, burning around the margins, drying up, or falling off, and the soil appears dry, water more.
To add to the challenge, soil that appears dry at the top, may be very wet a few inches down. And the opposite is true as well. All the more reason it is important to apply your detective skills based on observation and knowing how much or little you’ve been watering. Finally, winter conditions can be very dry. Occasional watering throughout the season may be necessary to prevent plants from becoming too dry. Roots are still growing and soil moisture is essential for proper establishment.
And don’t assume that once spring arrives, your supplemental irrigation duties are behind you. My case is a perfect example.
When spring arrived, it was unseasonably hot and dry. Even though I had been diligent about consistently watering through fall and into winter, many of my plants were not yet able to make it on their own without continual supplemental irrigation help from me. In fact, summer was even worse, with high steady temperatures and no rain. I spent hours every week going from plant to plant giving them a thorough soaking.
One of the best time-savers you can find to lighten the load and put some of your irrigation duties on auto-pilot is to use soaker hoses and/or drip irrigation combined with portable battery-operated timers. Perhaps my best specimen tree in my entire landscape was part of this transplanting challenge last fall. Without the help of my soaker hoses on timers, I’m not sure it would have survived the relocation. But now it’s thriving and I can safely say, having the right equipment on hand made the difference. If you have a tree or shrub you can’t afford to lose, invest in soaker hoses and timers. I cannot stress the importance of this enough!
When to Fertilize Trees and Shrubs?
Once you know your trees and shrubs have taken to their new environment through the successful establishment, you can now begin a fertilization routine to help feed your plants. But I don’t suggest fertilization until then. Otherwise, you’re putting undue stress on plants that don’t need to be exerting extra energy to put on new growth. Instead, until established, my opinion is that all energy should be concentrated on root development and basic establishment. Remember, you have to walk before you can run.
But when the time is right, I still like to play it safe. I use Milorganite®, a slow-release, non-burning fertilizer that I know will do the job without the risk of over-taxing my plants.
While the above steps are critical to success, there will never be a better time of year than fall to relocate trees and shrubs or plant new ones. It’s easier on you and the plants. Once established, you’ll be rewarded for your efforts forever more.
